Role Of Dynamic Contrast-Enhanced MRI In Evaluating The Association Between Background Parenchymal Enhancement And Breast Lesions

Objective:To evaluate the relationship between background parenchymal enhancement(BPE)on dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and breast cancer,and to explore whether there are differences in BPE among different breast cancer molecular subtypes,immunohistochemistry(IHC)markers and menopausal status.Methods:86 patients in our hospital which were confirmed to have breast lesions by breast MRI,surgery and pathology were enrolled in this study,30 with benign lesions and 56 with malignant tumors included.BPE of the contralateral breast was assessed qualitatively by two dedicated radiologists and quantitatively(using semi-automatic breast segmentation).Using independent sample t test or Mann-Whitney U test to compare quantitative parameter differences between the benign and malignant lesions,biomarkers and menopausal status.The quantitative BPE and FGT of different molecular subtypes were performed by One-Way ANOVA or Kruskal-Wallis H,pairwise comparison between groups was performed by Bonferroni-t or non-parametric test.Qualitative BPE and FGT distributions in each group were expressed as percentage or rate,and compared by chi-square test.Spearman rank correlation analysis was used to evaluate the correlation between FGT and BPE in breast lesions.P<0.05 was considered statistically significant.Results: Comparison of BPE and FGT in benign and malignant groups: the distribution proportion of benign lesions in the low BPE group(minimal and mild)was higher,and the distribution proportion of malignant lesions in the high BPE group(moderate and marked)was higher than that in the benign lesions,there were statistically significant difference of breast benign or malignant lesions and BPE(P<0.05).There was no statistical significance in the distribution of high and low FGT among benign and malignant lesions(P>0.05).Quantitative analysis showed that the BPE% of breast malignant lesions was significantly higher than that of benign lesions(P < 0.05),the difference of FGT% in benign and malignant lesions was not statistically significant(P>0.05).Qualitative BPE was moderate positively correlated with FGT(r=0.39,P<0.05).Comparison the BPE and FGT of different breast cancer molecular subtypes,IHC markers and menopausal status: There was significant difference in quantitative BPE among different molecular subtypes(P<0.05);BPE% in Luminal A tumors was lower than triple negative breast cancer(P<0.05);BPE% in Luminal B tumors was lower than triple negative breast cancer(P<0.05).There was no significant difference in the FGT%,distribution of BPE and FGT among different molecular subtypes of breast cancer(all P>0.05).Women with high BPE tended to have increased rate of HER-2 positive tumors(P<0.05).Compared with the postmenopausal patients,the premenopausal patients showed higher frequencies of high BPE(P<0.05);BPE% in premenopausal state was significantly higher than that in postmenopausal patients(P<0.05).The FGT% of ER negative expression was higher than that of ER positive group(P<0.05).Conclusions: High levels of BPE were associated with breast cancer,and there was a positive correlation between BPE and FGT.BPE showed significant differences in different molecular subtypes,BPE was significantly different in Luminal and triple negative breast cancers,and high BPE was associated with HER-2 amplification or protein overexpression.The premenopausal state of BPE was significantly higher than postmenopausal state,it was closely related to menopausal status.